This invention relates to devices for permitting access to the body through the skin, i.e., percutaneous devices, and more particularly to skin penetration devices which may be used as an access port into the body for extended periods of time.
Percutaneous access devices are useful when frequent or long-term access to the body is required, as in kidney dialysis, drug deliver, intravenous feeding, ostomies, and transmission of energy to intracorporeal blood pumps. Practical devices for long-term skin penetration in humans, however, have not been successful prior to the present invention because skin adjacent to the implanted devices will not heal to form a tight barrier to infection. Instead, when a foreign device is implanted for percutaneous access, epidermal cells begin to migrate, each seeking to surround itself completely with other similar cells. The epidermal cells thus grow down the sides of the device in an attempt to expel it. Deep sinus tracts form and body fluids are exuded at the interface between the device and adjacent tissue, forming a bed for infection. The percutaneous device, if not expelled spontaneously, must be removed to allow the infection to be cured.
Another drawback of presently available skin penetration devices relates to the difficulty of correcting problems with tubes mounted to, and extending through, such devices. Catheter tubes which are used, for example, in continuous ambulatory peritoneal dialysis or continuous infusion of drugs may become misaligned, kinked, blocked, or coated with fibrin. With existing technology such catheters cannot readily be removed without disturbing the percutaneous access device, and thus they must be surgically removed and replaced with another access device at a different site. Current technology does not, therefore, readily permit multiple use of an implanted percutaneous access device wherein one catheter may be substituted for another, nor does it allow catheter removal followed by plugging of the device for use at a later time.
Accordingly, it is an object of the invention to provide an improved percutaneous access device which promotes the formation of a tight barrier to infection and which allows replacement of tubes mounted to, and extending through, the device.
It is an object of the invention to provide a percutaneous access device which allows installation and replacement of tubes with minimal disturbance to the implanted device.